30-year-old systems engineer Haruki is overworked, clumsy and a person who is hard on himself and others. One day, he meets the kindly Katsumi, a 52-year-old gentleman who takes care of him when he was about to pass out. Haruki ends up asking him: ‘Please be my papa!’ and surprisingly, Katsumi agrees! As a pseudo 'father-son’, the two go to the zoo, a fireworks display etc so Haruki can have the experiences he missed out on during childhood.